Scaffolding Structure and Function in PBL¶

Strategy · All strategies
Evidence · 3 claims (2 for, 1 mixed) · 9 studies (3 causal, 2 quant-synthesis, 2 review, 1 qualitative, 1 theoretical), q2–q4 · 1 of 9 report an effect size

Description¶

This strategy embeds language scaffolds within project-based learning (PBL) so that students can demonstrate content understanding through academic language they might not yet command independently. Instructors supply structural supports — sentence starters ("The evidence shows that…"), conditional frames ("If ______, then ______"), and discourse templates for justifying, comparing, or hypothesizing — paired with explicit instruction in the function each structure serves (e.g., claiming, evidencing, conceding). The scaffold targets both the linguistic form and the rhetorical purpose, so students learn not just how to say it but when and why.

Design Implications¶

Language demands are a hidden source of extraneous load in PBL: students wrestling with how to phrase a claim have fewer resources for the reasoning itself Cognitive overload degrades learning. [+S]. Providing discourse structures externalizes that burden, and contingent support — offering stems only where students need them, then fading — improves outcomes Contingent scaffolding improves learning. [+M]. The critical design move is pairing structure with function: a stem taught without its communicative purpose becomes a fill-in exercise rather than a tool for disciplinary reasoning.

Context¶

Requirements¶

• Task analysis of the project's language demands: which functions (justify, predict, critique, summarize) the deliverables require
• Sentence starters and frames matched to those functions, modeled through Think-Aloud or worked examples of project discourse
• Explicit instruction on when each structure is appropriate, followed by Practice using it in authentic project talk and writing
• A fading plan: stems become optional, then are replaced by student-generated language

Constraints¶

• Over-reliance on stems can produce formulaic, low-cognitive responses; scaffolds must be faded as proficiency grows or they suppress rather than build capability Contingent scaffolding improves learning. [~M]
• Generic stems disconnected from the discipline's actual discourse conventions transfer poorly; "I think… because…" does not approximate how scientists or historians argue
• If scaffolds are assigned uniformly without diagnosis, they add redundant load for proficient speakers and under-support multilingual learners with different needs
• Heavy preparation burden: effective stems require analyzing the project's genuine communicative demands, not distributing a generic handout

Implementation Variability¶

• Speaking scaffolds: discussion stems for team meetings and critique protocols ("I agree with ___ because…", "What evidence do you have for…?")
• Writing scaffolds: paragraph frames for explanations and argumentation in project deliverables
• Genre scaffolds: full templates for project genres (lab reports, design justifications, persuasive pitches) with labeled rhetorical moves
• Proficiency-tiered stems: varied stem banks by language proficiency, with multilingual learners receiving more complete frames initially

Target Learners¶

• Multilingual learners and English language learners in PBL settings, who face the double demand of content and language acquisition [+M]
• Novices to a discipline's discourse conventions — all students new to academic argumentation benefit from seeing its structures made explicit
• Less beneficial, and potentially constraining, for students already fluent in the target discourse, for whom stems are redundant Worked-example guidance becomes less effective as learner expertise increases. [~M]

Target Learning Goals¶

• Disciplinary communication: expressing claims, evidence, and reasoning in field-appropriate forms
• Conceptual understanding: articulating reasoning forces consolidation of the underlying concepts
• Academic language development: acquiring structures that transfer across projects and subjects

Instructions¶

1. Analyze the project deliverables to identify the language functions students must perform (justify, compare, hypothesize, critique).
2. Draft stems and frames for each function, and model their use through a Think-Aloud or worked example of authentic project discourse.
3. Provide explicit instruction on form and function, then structure Practice opportunities in low-stakes project talk before graded work.
4. Monitor use, prompt students to revise formulaic responses, and progressively fade the scaffolds as proficiency develops.

Related Strategies¶

• Sentence Frames and Starters — the general-purpose version of this strategy, not tied to PBL contexts
• Activating Prior Knowledge — front-loads the conceptual vocabulary that stems then organize
• Structured Academic Controversy — a PBL discussion format that depends heavily on function-specific discourse stems
• Provide templates and publicly posted talk moves to scaffold discussion and lower cognitive load
• Assign a language function to each 5E phase (describe, compare and contrast, classify, classify with justification) and align language objectives with science objectives

Examples¶

• In a project-based science unit on ecosystems, students use "The data show that ___, which suggests that ___" when writing evidence-based claims, with the teacher modeling the move aloud before team investigations.
• EL Education (formerly Expeditionary Learning) curriculum modules build scaffolded language structures into every project's writing tasks, with frames tiered by language proficiency (eleducation.org).
• In a PBL civics project, discussion stems ("Our proposal addresses ___ by ___", "A counterargument is ___, and we respond by ___") scaffold team deliberation before the final presentation.

Key Sources¶

• van de Pol, J., Volman, M., & Beishuizen, J. (2010). Scaffolding in teacher–student interaction: A decade of research. Educational Psychology Review, 22(3), 271–296. doi:10.1007/s10648-010-9127-6
• Gibbons, P. (2003). Mediating language learning: Teacher interactions with ESL students in a content-based classroom. TESOL Quarterly, 37(2), 247–273. doi:10.2307/3588504
• Sweller, J., van Merriënboer, J. J. G., & Paas, F. (2019). Cognitive architecture and instructional design: 20 years later. Educational Psychology Review, 31(2), 261–292. doi:10.1007/s10648-019-09465-5
• Krajcik, J. S., & Blumenfeld, P. C. (2006). Project-based learning. In R. K. Sawyer (Ed.), The Cambridge Handbook of the Learning Sciences (pp. 317–334). Cambridge University Press.
• Zwiers, J. (2014). Building Academic Language: Meeting Common Core Standards Across Disciplines (2nd ed.). Jossey-Bass.